Chemistry of Dendritic Molecules Holds Growing Allure for Researchers
RON DAGANI · Chemical & Engineering News · 1993
Chemists' fascination with highly branched molecules—variously called arborols, dendrimers, or cascade molecules—is growing as new synthetic paths lead to materials with promising properties and potential new applications. Those properties and applications are only beginning to be explored. But two recently published papers—one from Italy and one from the U.S.—show how dendritic molecules are making inroads into unaccustomed realms like coordination chemistry and engineering plastics. In Italy, a team of researchers at the universities of Pisa, Messina, and Bologna has been using luminescent and redox-active transition-metal complexes as building blocks to construct treelike structures whose "branches" sprout from a central core. Their latest synthetic feat has been the creation of a 1090-atom supramolecular complex containing 22 ruthenium ions. This arborol, as they call it, is believed to be the largest transition-metal complex of its type ever made [ Angew. Chem. Int. Ed. Engl., 31, 1493 (1992)]. The structure is held together by the 22 ruthenium centers, which ...